AIM: To study the relationship between some serotonergicsubreceptors and sleep stages and the effects of immune promoterson sleep stages. METHODS: The EEG, EOG, and EMG ofrats were recorded before and after administration of drugs ip oricv. The changes of sleep stages were analyzed with automaticsleep analysis systems for rats. Radioligand assay to mensuratethe binding capacity of 5-HT_2 receptor to [~3H]ketamserin.RESULTS: Immune promoters such as transfer factor, muramyldipeptide, and TNF promoted sleep, especially deep sleep. Theeffects were closely related to the 5-HT level in the brain. Smalldosage of 8-OH-DPAT as 5-HT_(1A) (autoreceptors ) agonistmarkedly increased the ratio of ligh sleep and deep sleep, butdecreased the ratio of REM sleep. Ritanserin as a 5-HT_2 receptorantagonist showed the similar effects to small dosage of 8-OH-DPAT. The both together got an adding effect on light sleep anddeep sleep and synergistic effects on REM sleep. Stimulation of AIM: To study the relationship between some serotonergicsubreceptors and sleep stages and the effects of immune promoterson sleep stages. METHODS: The EEG, EOG, and EMG ofrats were recorded before and after administration of drugs ip oricv. The changes of sleep stages were analyzed with Radioligand assay to mensurate the binding capacity of 5-HT_2 receptor to [~ 3H] ketamserin .RESULTS: Immune promoters such as transfer factor, muramyldipeptide, and TNF promoted sleep, especially deep sleep. The effects were closely related to the 5-HT level in the brain. Small dosage of 8-OH-DPAT as 5-HT (1A) (autoreceptors) agonistmarkedly increased the ratio of ligh sleep and deep sleep, butdecreased the ratio of REM sleep. Ritanserin as a 5-HT_2 receptorantagonist The same together to small dosage of 8-OH-DPAT. The both together got an adding effect on light sleep and sleep and synergistic effects on REM sleep. Stimulation of